Apparatus for and process of amalgamating ores of gold and silver



(.No Model.)

A. E. G'RIFFITHSQ APPARATUS FOR AND moonss 0F AMALGAMATING 035s OF GOLD AND SILVER.

No. 249,925. Patented Nov. 22,1881.

N. PUERS. F'hulnLlhog UNtTEn STATES PATENT AMOS E. GRIFFITHS, OF PHILADELPHIA, PENNSYLVANIA.

APPARATUS FOR AND PROCESS OF AMALGAMATING ORES 0F GOLD'AND SlLVER.

SPECIFICATION forming part of Letters Patent No 249,925, dated November 22, 1881.

Application filed July 23, 1881.

T 0 all whom it may concern:

Be it known that I, AMos E. GRIFFITHS, a citizen of the United States, residing at- Philadelphia, in the county of Philadelphia and .State of Pennsylvania, have invented certain and to an improved process of producing the amalgamation of such ores and separating therefrom the precious metals; and theobjects of vmyimprovetnents are, first, to produce a novel apparatus for receiving and mixing the ores and the ingredients hereinafter named; and, second, to extract or separate the precious metals-such as gold and silver-from ores containing tellurium and other base metals, the invention consisting in certain combinations of devices which constitute a mixing apparatus, into which the materials hereinafter named are placed for the purpose of mixing them with and amalgamatin g the ores, and, further, in the hereinafter-described process of amalgamating the ores after they have'been mixed with chemicals and placed in the apparatus, as will be more fully described hereinafter.

The drawing represents a side view of the apparatus, partly in section, in which- A represents a tight case or jacket, preferably of iron or other strong metal plates,properly secured together to be air-tight.

B is a horizontal shaft, placed centrally in the case A, and is revolved at the proper speed from any convenient power through the bandpulley B, it being placed in proper bearings b at each end of the case.

0 '0 are agitator-arms, secured or attached to the shaft B by any proper means, so as to revolve within the case A as said shaft revolves. There may be as many of these arms (No model.)

as may be found most useful in practice, and they may be so attached to shaft B as to be in line; or they may be spirally attached thereto, or in any other position found best to accomplish the work.

D D are a series of cast-iron balls placed between the paths of revolution of the arms 0, of ,which balls there may be as many as there are spaces between the arms or not, as found best in practice.

E is a steam-pipe, having its inlet end outside of and above the case A, while its horizontal part is at the top and within said case, and perforated, so that the steam entering the inlet 0 will be free to pass through the perforations e into the case, as indicated by the arrows, and heat the contents thereof.

la is the exit end of steam and air escape pipe I, which has a stop-cock, F, placed above the case A, so as to stop the steam from passing out at exit 6 until the contents of the case are sufficiently heated, when the stop-cock is opened and steam allowed to escape.

G is an opening in the top of case A for the purpose of feeding in the ores or pulp to be acted upon, and G is a screw-valve to close the opening air-tight after the charge is in the case.

est or most convenient part of the case, for the purpose of discharging the contents thereof after such contents have been treated. There may be one or more such openings, as required for the purpose, they being closed by means of a stopcock or valve.

In order to effectually carry out the hereindcscribed process so far as it is independent of the mechanism used, the ores are first heated to a cherry-red heat in the usual manner, and then ground in a mill to a fine powder, a quantity of which is placed in the apparatus, to which the ingredients hereinafter named are to be added. Supposing the amount of ore thus placed to be one ton, then there is added about two pounds of powdered ferro-manganese, dry, which is to be thoroughly mixed with the ore, and enough water added to completely saturate thetmass. I then take about ten pounds of bichloride of mercury and dissolve it in warm water and add it to the sat H is an opening in one end and at the lowurated ore in the apparatus. About two pounds of carbonate of soda is then dissolved in water and also added to the mass. After this has been done and the apparatus tightly closed, steam is admitted until the whole contents are heated to the desired temperature, when the revolving shaft and its agitators are put in motion, thoroughly mixing the pulp and chemicals in one mass, the chemicals being thus brought in contact with the particles of metal contained in the pulp. The iron contained in the powered ferro-manganese is acted upon by the chlorine of the bichloride of mercury,causing the mercury to attack the precious metalscontained in the powered ores. By this means chloride of iron, metallic mercury, and amalgam of the precious metals are formed, and the loss caused by the flouring of mercury, which occurs in the amalgamating processes now in use, is avoided.

By the ordinary methods of amalgamating gold and silver ores, whether in stamp-battery, arrastras, or pans, &c., a large loss'of quicksilver occurs, by reason of the flouring or granulation of this metal, whereby it is cut up into fine particles, which are lost in the tailings. These fine globules of mercury become coated with impurities, and so lose their power of cohesion, and while in this condition it is almost impossible for them to be brought together again in a mass. The floured quicksilver is that portion which is richestin precious metals, and this, as a matter of course, is lost along with the mercury. The solution of the carbonate of soda is intended to remedy this by cleansing the powdered ores and particles of metals from these impurities, thereby enabling the quicksilver to unite with the metal and form amalgam.

When the mass in theapparatus has become thoroughly mixed and the pulp and chemicals brought into contact with the particles ofmetals contained in the pulp, and properly amalgamated, the charge is drawn off or removed from the apparatus and the amalgam washed, collected, and retorted off in the usual manner.

Referring to that part of myinvention which relates to the apparatus,I desire to say thatI am aware that it is not novel to use agitators in a closed vessel for mixing the pulp therein. I am also aware that it is not novel to use balls of metal in a revolving cylinder for the purpose of trituratin g ores, and that it is not novel, broadly considered, to apply heat to the mass while in the apparatus, such features being separately shown in the following-named patents: J. H. Sweet, February 10, 1852, N 0. 8,727; A. Bassett, January 27, 1867,No. 61,383; Kirk and Ayers, July 21,1874,No. 153,171, and English patent of 1857, No. 1,688, none of which, as shown and described, do I make any claim to, as none of them show the combination of devices claimed by me.

In relation to the process claimed by me, I desire to state that I am aware of the patents granted to F. Dibben, July 2, 1861, No. 31,686, and P. G. L. G. Designolle, June 15, 1880, No. 228,970, in both of which their operation is dependent upon magnetic or electric action, and hence I do not claim what is therein shown or described but,

Having thus described my invention, what I do claim, and desire to secure by Letters Patent, is

l. The combination of the case or jacket A, revolving shaft B, having agitators 0, iron balls D, and steam-pipe E, the parts being constructed and operating substantially as and for the purpose described.

2. The herein-described process of amalgamating ores of the precious metals, which consists in mixing with the pulverized ores a certain proportion of powdered ferro-manganese and then adding a solution of bichloride of mercury and a solution of carbonate of soda, substantially in the manner and for the purposes described, the mass being agitated and subjected to the action of heat, as set forth.

In testimony whereof I aflix my signature in presence of two witnesses.

AMOS E. GRIFFITHS.

Witnesses:

THOS. F. SHEWELL, WM. M. MCKNIGHT. 

